Avens Publishing Group Inviting Innovations Open Access Review Article J Hum Anat Physiol July 2017 Volume:1, Issue:1 © All rights are reserved by Ogeturk. AvensJournal Publishing of Group Inviting Innovations Human Anatomy The Prefrontal Cortex: A Basic & Physiology Embryological, Histological, Anatomical, and Functional Ramazan Fazıl Akkoc and Murat Ogeturk* Department of Anatomy, Firat University, Turkey Guideline *Address for Correspondence Murat Ogeturk, Firat University, Faculty of Medicine, 23119 Elazig, Turkey, Tel: +90-424-2370000 (ext: 4654); Fax: +90-424-2379138; Keywords: Prefrontal cortex; Working memory; Frontal lobe E-Mail: [email protected] Abstract Submission: 24 May, 2017 Accepted: 11 July, 2017 The prefrontal cortex (PFC) unites, processes and controls the Published: 19 August, 2017 information coming from cortex and subcortical structures, and Copyright: © 2017 Akkoc RF. This is an open access article distributed decides and executes goal-oriented behavior. A major function of PFC under the Creative Commons Attribution License, which permits is to maintain the attention. Furthermore, it has many other functions unrestricted use, distribution, and reproduction in any medium, provided including working memory, problem solving, graciousness, memory, the original work is properly cited. and intellectuality. PFC is well developed in humans and localized to the anterior of the frontal lobe. This article presents a systematic review and detailed summary of embryology, histology, anatomy, functions and lesions of PFC. I. Lamina zonalis: Contains few Cajal horizontal cells. The axons of Martinotti cells located at deep layers, the last branches of the apical dendrites of pyramidal cells, and the last branches Introduction of the afferent nerve fibers extend to this lamina. The prefrontal cortex (PFC) is the largest cortical area in the II. Lamina granularis externa: Harbors granular cells and some human brain, making up 29% of the whole cerebral cortex. It is small pyramidal cells. located in the frontal lobe, anterior to the primary motor cortex and the premotor cortex. PFC has key roles in defining personality and III. Lamina pyramidalis externa: Harbors loosely arranged behavior. It also has many functions including maintaining attention, pyramidal cells, which generally show an increase in size from planning complex movements, controlling emotions, discriminating outside to inside. The axons of these cells traverse the white between good and bad, speech, memory, temporal perception and matter and reach other cortical regions. The axons of these working memory [1-9]. cells make up the ipsilateral and contralateral cortico-cortical connections. Embryology IV. Lamina granularis interna: It is the layer with the highest The nervous system in humans first emerges at the beginning of number of cells. It harbors stellate pyramidal cells and the third gestational week as a neural plate as part of the ectodermal granular cells. plate. At the fourth week, three dilatation areas called the primary brain vesicles form. These are, in order from anterior to posterior, V. Lamina pyramidalis interna: Contains less number of cells in prosencephalon (forebrain), mesencephalon (midbrain), and comparison to the other laminae. It harbors well-developed rhombencephalon (hindbrain) [10]. pyramidal cells and Martinotti cells. The axons of the pyramidal cells located in this layer send projection fibers to At the fifth week, prosencephalon divides into two brain the basal ganglia. vesicles called the telencephalon and diencephalon. At the end of the fifth week, two lateral diverticula develop, which are named as VI. Lamina multiformis: Harbors Martinotti cells, fusiform cells telencephalic vesicles. These two vesicles are the primordial forms of and pyramidal cells [12,13]. the cerebral hemispheres [10,11]. Anatomy The developing cerebral hemispheres are initially like three Frontal lobe constitutes the whole cerebral cortex area anterior to characteristic layers of the neural tube (ventricular, intermediate, and the central sulcus. It has three parts. The narrow area anterior to the marginal). Later, a fourth layer develops, and the cells in this layer central sulcus is primary motor cortex (Brodmann 4), and the area migrate to the marginal layer to form the cortex. The surface of the immediately anterior to the primary motor cortex is premotor cortex cerebral hemispheres is initially straight. However, fissures, sulci and (Brodmann 6). PFC comprises the anterior part of the frontal lobe, gyri begin to form as the brain grows [10,11]. located anterior to the premotor cortex [7,14]. Histology PFC is made of the superior frontal gyrus, medial frontal gyrus, PFC is comprised of six laminae that cannot be clearly most part of the inferior frontal gyrus, a great portion of the part of distinguished from each other histologically. From inside to outside, superior frontal gyrus and frontal gyrus that is on the inner surface of these laminae are: the hemisphere, and anterior part of cingulate gyrus (Figure 1) [15]. Citation: Akkoc RF, Ogeturk M. The Prefrontal Cortex: A Basic Embryological, Histological, Anatomical, and Functional Guideline. J Hum Anat Physiol 2017;1(1): 4. Citation: Akkoc RF, Ogeturk M. The Prefrontal Cortex: A Basic Embryological, Histological, Anatomical, and Functional Guideline. J Hum Anat Physiol 2017;1(1): 4. ISSN: 2575-7563 There are three parts of PFC, namely the lateral PFC, medial PFC and orbital PFC (orbitofrontal cortex). I. Lateral prefrontal cortex: It is comprised of Brodmann’s areas 8, 9, 10 and 46. Additionally Brodmann’s areas 44, 45 and 47 are also included in the lateral PFC (Figure 2) [17-19]. In literature, some sources cite Brodmann’s areas 45 and 47 as ventrolateral PFC, and Brodmann’s areas 9 and 46 as dorsolateral PFC. Additionally, the frontal pole, which is the most anterior part of the frontal lobe and is Brodmann’s area 10, is named as rostral or polar PFC [20-22]. II. Medial prefrontal cortex: The medial PFC includes Brodmann’s areas 8, 9, 10 and 12, and Brodmann’s areas 14, 24, 25 and 32 that are located anterior to cingulate gyrus (Figure 3) [17,23]. Figure 3: Medial view of Brodmann’s areas 8, 9, 10, 11, 12, 24, 25 and 32 III. Orbital prefrontal cortex [orbitofrontal cortex]: Brodmann’s (Pencil drawing modified from Putz R) [16]. areas 11, 12, and 13 constitute the orbital PFC (Figure 3). Orbital PFC is anterior to the PFC and surrounds the medial orbital sulcus and lateral orbital sulcus [17,21,22]. PFC has vital functions including thinking, reasoning, prospective planning, conforming to the learned social rules, politeness, accurate Functions of prefrontal cortex decision making for sustaining life and executing these decisions. The principle function of PFC is to plan and execute behaviors Additionally, morale motivation, self-control ability, common [24]. PFC collects information from cortex and subcortical structures, sense, taking lessons from errors and feeling empathy are among the and arranges and controls this information; decides and executes the functions of frontal cortex [19,25-27]. behavior [8]. PFC owns a “working memory” feature, which is the ability to follow different kinds of information simultaneously and to immediately utilize this information by combining them with the following thoughts. Another function of PFC is the elaboration of thoughts, that is, developing depth and abstractness to the information [3,4,28]. The working memory of PFC executes the storage of transient memory information, temporal perception, foresight, prospective planning, deciding whether the stimulus is behavioral or not, preparing planned and logical response to the sensory signal, solving complex mathematical, ethical, moral and conscientious problems, and controlling whether behaviors are within moral rules or not [25,27,28]. PFC has been shown to play a key role in remembering old information and recalling new memory [29]. Figure 1: Superior, medial and inferior frontal gyri, and orbital gyri (Drawing modified from Putz R) [16]. One of the main functions of PFC, particularly the dorsolateral section is the attention. It blocks distracting external stimuli and allows focusing and giving attention to a particular task [1,24]. The main function of Brodmann’s area 46 that is included in the dorsolateral PFC is working memory and processing of cognitive information [22,30]. The main function of Brodmann’s area 11 that is included in the orbital PFC is processing emotions and values. Brodmann’s area 47 that is included in the ventrolateral PFC is functions in feeling empathy, and this area activates during an automatic action. Additionally, Brodmann’s area 47 in the left hemisphere plays a key role in wording function [22,30]. Brodmann’s areas 14, 24, 25 and 32 that constitute the medial PFC are parts of the limbic system. Due to the connection of medial PFC with the limbic system, it functions in processing and enhancement Figure 2: Lateral view of Brodmann’s areas 8, 9, 10, 46, 44, 45 and 47. of memory. Additionally, medial PFC is associated with most high (Pencil drawing modified from Putz R) [16]. cognitive functions [23]. J Hum Anat Physiol 1(1): 4 (2017) Page - 02 Citation: Akkoc RF, Ogeturk M. The Prefrontal Cortex: A Basic Embryological, Histological, Anatomical, and Functional Guideline. J Hum Anat Physiol 2017;1(1): 4. ISSN: 2575-7563 Ventrolateral PFC has a critical role in the formation of new 2. Oren N, Shapira-Lichter I, Lerner Y, Tarrasch R, Hendler T, et al. (2016) How episodic memories [31]. attention modulates encoding of dynamic stimuli. Front Hum Neurosci 10: 507. Lesions of the prefrontal cortex 3. Ustün S, Kale EH, Cicek M (2017) Neural networks for time perception and working memory. Front Hum Neurosci 11: 83. PFC is highly developed in humans. The lesions of the PFC can be caused by various reasons including trauma, surgical interventions, 4. Murray JD, Bernacchia A, Roy NA, Constantinidis C, Romo R, et al. (2017) infections, toxins, chemicals, narcotic drugs, alcohol and chronic Stable population coding for working memory coexists with heterogeneous neural dynamics in prefrontal cortex.